Preparation: In a large bowl, alternative layers of tomatoes and onions, sprinkling each layer with salt. Let stand for at least 8 hours or overnight. Rinse; drain well. Combine vegetables with vinegar , sugar, and spice bag. In a large saucepan or stock pot, bring mixture to a boil, then simmer, uncovered, for about 30 to 45 minutes, stirring frequently until slightly thickened. Pour into hot, sterilized jars and seal. Yield: Approximately 12 cups ( 3 Liters) Recipe Source: A Taste of Quebec by Julian Armstrong (Hippocrene Books) Reprinted with permission.